This proposed study is a cooperative one involving two components of the University of Mississippi. We propose to enroll 225 borderline hypertensive individuals (DBP 85-95 mm Hg) who are moderately overweight (120-150% of ideal weight). They will then be enrolled in the following dietary change programs: 1) weight loss, 2) weight loss plus increased calcium, 3) weight loss plus increased exercise, and 4) weight loss plus increased potassium (the last condition only at the Jackson site). Participants who are to undergo the weight loss and exercise protocol will have determination of fitness (treadmill) made at baseline and at follow-up. The primary purpose of this phase of the study is to determine ability to change intervening variables. However, differences in blood pressure fall between the control group and each of the dietary and other change variables should be able to be determined, although clear differences between the dietary groups in blood pressure is unlikely to be seen. Studies of red cell flux will be done to see if these correlate with response to dietary change.